This invention relates to the slitting of overwidth metal strip and, more particularly, to simultaneously slitting an elongated metal strip into two lengthwise pieces while trimming the side edges of the strip.
Flat mill products such as elongated metal strips having thicknesses of less than about a quarter of an inch and various widths and lengths have long been produced in the ferrous and the nonferrous metal industries. A general discussion of practices and equipment for producing and processing metal strip, including slitting, may be found in the Metals Handbook published by the American Society of Metals ("ASM") and The Making, Shaping And Treating of Steel, presently published by the ASM.
Heretofore in some production facilites, metal strips having thicknesses of more than about one sixteenth of an inch and lengths of up to about twenty-five feet (25') can not be adequately held in alignment on feeding tables or conveyors associated with slitters as they being cut to specification. Thus, for example, in a production facility for shearing zirconium strips having thicknesses of from about one sixteenth of an inch to about one eighth of an inch, and widths of about twenty three inches (23") and lengths of about fifteen feet (15') or more into several pieces and trimming the edge sides of the strip, excessive handling is required because the shear can only cut strips of up to ten foot (10') in length and can only perform one cut at a time. The workmen must move each strip to a shear where they mark three cut lines on the strip. The strip is then loaded onto the shear and double cut (i.e., one cut from the front edge and a second cut from the trailing end) to trim one half inch from the side edge. The strip is then reversed and double cut to trim one half inch from the other side edge. The trimmed strip is then centered in the shear and double cut a third time to shear the strip in half lengthwise. This extensive handling of each strip frequently leads to scratches and other surface defects which are costly to repair.